California reports first increase in groundwater supplies in four years

SACRAMENTO, Calif. — After massive rainstorms flooded California’s rivers and blanketed mountains with snow, the state on Monday reported the first increase in groundwater supplies in four years.

The state saw 4.1 million acre-feet of managed groundwater recharge in the water year ending in September, and an 8.7 million acre-foot increase in groundwater storage, according to California’s Department of Water Resources. Groundwater supplies are critical to growing much of the country’s fresh produce.

The biannual report came after water officials stepped up efforts to capture flows from mountain snowmelt during last year’s rains and encouraged farmers to flood fields to replenish groundwater basins.

“The impressive recharge figures in 2023 are the result of hard work by local agencies combined with committed efforts from the state, but we need to do more to be prepared to capture and store water when the wet years arrive,” says Paul Gosselin, deputy director of sustainable water management for the agency, said in a statement.

California has been trying to increase groundwater recharge as increasingly drier years are expected due to climate change. Much of the state’s population relies on groundwater for drinking water in their homes, and farmers who grow much of the country’s food depend on the precious resource for crops ranging from carrots and almonds to berries and leafy greens.

For years, Californians pumped groundwater from wells without measuring how much they used. But when some wells dried up and the land began to sink, the state passed a law requiring local communities to measure and regulate groundwater pumping to ensure the basins would remain sustainable for years to come.

In Monday’s report, California water officials noted that some areas where land had sunk experienced a recovery as users pumped less groundwater because more surface water was available after the rain. In total, the state extracted 9.5 million hectares of groundwater in the last water year, up from 17 million a year earlier, the report said.

Some California farmers have reported seeing a rebound in their wells this year, prompting them to wonder how much the state needs to reduce groundwater pumping. Joaquin Contente, a dairy farmer in the crop-rich San Joaquin Valley, said he has seen recovery in his wells, with one well returning to a depth of 18 feet (from more than 30 feet deep two years ago).

“They are already back to almost normal levels,” he said.

California water officials welcomed the recharge, but said it would take five rainy years like last year to boost groundwater storage to the level needed after so many years of overpumping.